The present invention generally relates to soft tissue implants and more specifically relates to soft tissue implants designed to enhance fixation in the body and/or alter or reduce capsular formation.
Soft tissue implants, particularly mammary prostheses, are plagued by problems of capsular formation and contracture. Soon after an implant is placed into the body, an inflammatory response begins to deposit a fibrous capsule around the implant. In most cases, particularly for relatively large and smooth implants, the capsule is comprised of highly organized or aligned collagen fibers. As the capsule matures, certain events may trigger the differentiation of fibroblasts to a contractile phenotype (myofibroblasts). In this or similar scenarios, and if the collagen fibers are aligned, capsular contracture may ensue.
Capsular contracture can be debilitating to the patient because of discomfort or even pain caused thereby, can diminish the efficacy of the aesthetic results in both the look and feel of the implant, and can sometimes damage the implant itself. Problems with capsular formation and contracture occur in many implant types such as pacemakers, dura matter substitutes, implantable cardiac defibrillators, pacemaker leads, hernia repair meshes as well as breast and other esthetic implants.
It has been established in the literature that surface texturing of implants often helps to reduce the incidence of capsular contracture when compared to smooth surface implants. Furthermore there is increasing evidence regarding the ability of foam covered implants, for example, polyurethane foam coated implants, to reduce contracture rates. However, polyurethane foam coatings are biodegradable and lose their efficacy once the polyurethane degrades. Further, it can be appreciated that degradation of polyurethane foam into the body is undesirable and potentially unhealthy.
The present invention addresses at least some of these drawbacks of conventional implants.